Spew on Leather – Not what you think!!

Spew on Leather

Spew on leather has become more common – read on to find out why and what can be done to solve the problem

What is Spew on leather?

The term Spew or Spue is not what you might think!!

Nothing to do with a good night out or feeling ill!
Spew actually refers to the migration of fats/oils from within the leather that crystallize on the surface when they meet the air.
The crystals form on the surface as a white powder or as a ‘bloom’ but are often mistaken for mould or mildew.
The key indicator that you have Spew rather than mould is that Spew is very white in appearance. Mould tends to be green/grey in colour particularly on leather.
Spew can look very powdery (like salts on brickwork) and will be slightly waxy in appearance (try rubbing a bit between your fingers and you will feel this).

Spew forms from the natural fatliquors used during the tanning process and can be caused by a fault during the manufacturing process (usually insufficient degreasing) which is then exacerbated by changes in humidity and temperature.

Spew has become much more common in recent years due to the vast distances that leather and furniture now travels during its production where it is exposed to vast humidity and temperature changes which upset the balance of the fatliquors in the leather which then migrate to the surface.

Another factor that needs to be considered is that Spew can also be caused by the addition of fats or oils as surface dressings on the leather.
Over the years it was thought that ‘conditioning’ leather by using products containing fats and oils to the surface of the leather would extend its life. Now, of course, we know this not to be the case and often using ‘conditioners’ that contain fats or oils can result in spew formation.

To identify Spew simply heat with a hair dryer and it will disappear but will then reappear on the surface.

How can we treat Spew on Leather?

Spew cannot be resolved simply by cleaning but fortunately dealing with Spew is a relatively straight forward process – all you require is a correctly formulated Spew Stabiliser which will remove the spew from the surface of the leather and restabilise the fatliquors to prevent them coming back to the surface

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Judyb is respected throughout the world as an expert on leather and its care and restoration
Founder of the very first dedicated Leather Training School in the UK she is now Technical Director and Course Instructor at LTT Leathercare Ltd sharing her knowledge and advice with delegates from many countries
Judyb gives technical support and advice to the cleaning, detailing, manufacturing and retail sectors as well as advising consumers on care of their furniture in the domestic environment